Appendix II. 877 A, thus recording a time-temperature curve. The temperature scale is graduated by reference to well-known phenomena, whose FJUV. 836. temperatures have been accurately obtained by the methods on p. 587, and the junction at A should directly touch the source of heat. P. $pj. Steam Drier or Separator.—This apparatus is now considered essential to an engine steam-pipe, especially if the or length of the latter be great, and the principles embodied in various forms may be illustrated by Fig. 837. Steam enters at A, and in passing round the helix to escape at c, deposits all the moisture on the casing wall by centrifugal action, only dry steam passing away.